Proposal code

w013

Proposal title

Search for the smallest structure in the Galactic molecular clouds

The

Investigators and their

Affiliations

P.I. Hiroshi Imai Astronomical Institute, Tohoku Univ., Japan
Seiji Kameno VSOP project, NAO, Japan
Kazuyoshi Sunada Nobeyama Radio Observatory, NAO, Japan
Tetsuo Sasao Mizusawa Astrogeodynamics Obs., NAO, Japan

Proposal Abstract

We propose trial observations to search for the smallest structure in the Galactic molecular clouds by detecting spatial contrast and its time variation in the profiles of formaldehyde absorptions towards extragalactic radio sources. The previous observtions suggest gas structure smaller than 10 AU, but have never found any lower cutoff of the structure size. High mapping quality and spatial resolution of VSOP should reveal fine structure of the background extragalactic sources and their time variations, and be free ideally from beam dilution to smear the absorption profiles. We propose to observe suitiable strong sources near the Galactic plane, 0212+735, DA193, 0528+134, and NRAO530 in two observing sessions for the each source. Such a study makes us understand a universal picuture for interstellar molecular clouds and how density contrast and turbulence, which affect star formation, are created.

The full Cover Sheets (compressed post-script, typically 50kbytes) can be retrieved. Note that many proposals were reduced in extent by the Scientific Review Committee (e.g. by reducing the number of experiments), however the Cover Sheets contain the full proposal as submitted. Also note that AO2 proposals were submitted in May 1998, and information such as affiliations and contact details has changed for some proposers since that time. The Cover Sheets (and the details on this page, which were derived from the Cover Sheets) may therefore have changed.